Also known as "feedback." It is the feedback sound to a microphone from a loudspeaker. It makes a whistling noise by electrical oscillations.
In LP-record playing, an undesirable sound that is caused by vibrations from the loudspeaker creating extra vibrations in the cartridge stylus.
Feedback, the dreaded "sound man's (and sound woman's)curse," is caused by a regeneration of sound leaving a speaker and entering a microphone. This tone - a sustained shriek - is a self-perpetuating cycle which can be stopped by decreasing the volume. Sometimes referred to as a standing wave.
Howl or whistle caused by the recirculation of acoustic output of an amplifying system. In a hearing aid the sound emanating from the receiver may reach (or feed back into) the microphone and be reamplified until it builds up into a high-pitched whistle.
A squealing sound when the output of an audio circuit is fed back in phase into the circuit's input.
Unwanted mechanical interaction between output and input of an audio system, such as that between loudspeaker and microphone or turntable cartridge. Also called Positive Feedback.
A squealing sound when the audio output of a P.A. system is picked up by a microphone and sent, in phase, back into the mixer's input.